Top comb for a combing machine

ABSTRACT

In a top comb for a combing machine, having at least one row of stamped needles that are arranged in a parallel side-by-side relation and enclosed between two cover plates with a free needle projection ( 8 ) being left free, wherein compressed air channels are formed between the cover plates and adjacent pairs of needles are provided, in order to increase the efficiency of the cleaning effect, that the needles ( 1,1′,1 ″) incorporate embossings such that the congruent embossings of adjacent needles form an air channel ( 9,9′,9 ″), wherein the embossings taper in their widths towards the outlet area (outlet opening  11,11′,11 ″).

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention is directed to a top comb for a combing machinecomprising at least one row of stamped needles that are arranged in aparallel side-by-side relation and enclosed between two cover plateswith a free needle projection being left free, wherein compressed airchannels are formed between the cover plates and adjacent pairs ofneedles. A top comb of this type is known from EP 0 351 443 C1.

2. Prior Art

During the combing process particles and fiber residue deposit on thefree needle projection that interfere with the combing quality. Tocounter these deposits, mechanical cleaning devices were initially used.A significant improvement was attained with a pneumatic cleaning of theneedle projection, as it is described in EP 0 351 443 C1.

OBJECT AND SUMMARY OF THE INVENTION

With this as the starting point, the invention is based on the object offurther increasing the effectiveness of the cleaning effect in apneumatically cleaned top comb of the above type.

This object is met according to the invention in such a way that theneedles have embossings such that the congruent embossings of adjacentneedles form an air channel and the embossings narrow in their widthstoward the outlet area.

Due to this narrowing and, hence, reduction in cross section, anincrease is attained in the flow velocity of the exiting airflow, sothat the same can be used even more effectively for cleaning.Furthermore, the airflow can also be directed even more specificallytoward those sections of the free needle projection where particularlyheavy impurities are deposited.

In a further design of the invention, provision is made for at least onecover plate to have a free projection in the outlet area and to be bentinward under formation of an air conducting zone. This supports thetargeted guiding of the airflow.

Provision may furthermore advantageously be made for the embossings inthe needles to extend into the region of the free needle projection.This provides for a certain guiding of the airflow even after it hasleft the zone that is covered by the cover plates.

The cover plates advantageously project beyond the needles at their topsides and an air supply channel and/or an air distribution channel isformed in this region by means of a deep-drawing of the cover plates. Inthis manner, the compressed air coming from a compressed air source canbe distributed to the channels that are formed between the individualneedles.

Lastly, provision may be made for an airflow divider to be formed in theair channel. This creates two partial airflows that can be directedspecifically, for example, toward the front edge and the rear edge ofthe needle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below based on preferredembodiments in conjunction with the drawing.

FIGS. 1 through 3 show different embodiments for the configuration ofthe air channels in an inventive top comb.

FIG. 4 shows a cross-section through the top comb along sectional line4—4 of FIG. 2.

FIG. 5 shows a cross-section through the top comb along section line 5—5of FIG. 2 and

FIG. 6 shows a perspective view of a single needle of the top comb ofFIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

A top comb shown in FIG. 1 comprises a row of needles 1 that aredisposed side by side, which are covered by a front and rear cover plate3 and 4 relative to the direction of movement (arrow 2) of the sliver.The front cover plate 3 and the rear cover plate 4 each have top endsthat projects beyond the needles. A convexity 5 produced bydeep-drawing, which, together with the projecting portion 6 of the rearcover plate 4, forms an air distribution channel 7.

The needles 1, in the region of their free needle projection 8, aretapered in their thickness and sharpened by means of embossing. An airconducting channel or depressions 9 which can also be formed byembossing, which is delimited on its one side by the front cover plate 3and on its other side by the non-depressed sections 10 of two givenadjacent needles 1. The air channel 9 tapers towards the outlet opening11, which accelerates the air flow and specifically directs the same tothe front edge 12 of the needle 1, viewed in the combing direction.

FIGS. 2 and 6 shows a needle 1′, in which the air channel (depression)9′ is delimited by two non-depressed areas 10′ and outlet opening 11′.

FIGS. 4 and 5 show cross-sections through needle 1′ illustrating thetamper of the width of the depression towards outlet opening 11′ and theclosing of air channel 9′ by the outer side of an adjacent needle 1′.

FIG. 3 shows a needle 1″ wherein the air channel (depression) 9″ isdelimited by two non-depressed areas 10″, wherein additionally, however,an airflow divider 13 is provided in the form of a non-depressed sectionwhereby the airflow in the air channel 9″ is divided and routed to twoseparate outlet openings 11″.

In the embodiments according to FIGS. 2 and 3, the cover plates are notshown in the drawings. Regarding the front cover plate 3, provision maybe made for the same to have a free projection 14, which may be bentinward compared to the illustration in FIG. 1 under formation of an airconducting zone, so that the air is directed to the front edge 12 of thefree needle projection 8 in an even more targeted manner.

What is claimed is:
 1. A top comb for a combing machine, comprising atleast one row of stamped needles that are arranged in a parallelside-by-side relation and enclosed between two cover plates with a freeneedle projection being left free, wherein compressed air channels areformed between the cover plates and adjacent pairs of needles, whereinthe needles (1, 1′, 1″) incorporate depressed sections such that thecongruent depressed sections of adjacent needles form an air channel (9,9′, 9″) which is closed between an inlet and an outlet respectively atopposite ends of the air channel, the depressed sections tapering intheir widths towards the outlet (11, 11′, 11″).
 2. A top comb accordingto claim 1, wherein at least one cover plate (3) in the outlet area hasa free projection (14) and is bent inward under formation of an airconducting zone.
 3. A top comb according to claim 1, wherein thedepressed sections in the needles (1) extend into the region of the freeneedle projection (8).
 4. A top comb according to claim 1, wherein thecover plates (3, 4) project beyond the needles (1) at their top ends andwherein an air supply channel and an air distribution channel (7) areformed in this area by means of a deep-drawing of the cover plates (3,4).
 5. A top comb according to claim 1, wherein an air distributor (13)is formed in the air channel (9″).
 6. A top comb according to claim 1,wherein the depth of the cutout sections decreases towards the outlet.7. A top comb according to claim 1, wherein the depressed sections areformed by embossing.